<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <!-- 内联javaScript -->
  <button onclick="alert(' have a try!! 奋斗！！！')" type="button">555</button>

  <script src="./js/my.js">
    // 中间不写内容，写了也不实现
  </script>
</body>

</html>